This is the latest DS18B20 1-Wire digital temperature sensor from Dallas Semiconductor. Measures temperature in degrees C with 9 to 12-bit precision from -55C to 125C (+/-0.5C). Each sensor has a unique 64-Bit Serial number built-in allowing many sensors to be connected to the same one wire data bus. It is a state of the art computer-like component for many data-logging and temperature control projects.